INDEX 



Affinities, 29 ; method of determining, 

 31 ; necessity for studying, 33 ; chemi- 

 cal, hypothesis of, 254. 



Alimentary canal, effects of drink upon, 

 118. 



Animals, study of, 10 ; constitute a 

 linear series, 38 ; locomotion of, 47 ; 

 main faculties of, 48 ; definition of, 53 ; 

 limits of their multiplication, 54 ; 

 fourteen classes of, 131-133 ; table 

 showing their origin, 179 ; their dif- 

 ferentiation from plants, 195 ; food of, 

 197 ; torpidity in, 198-9. 



Annelids, first established, 65 ; definition 

 of, 87 ; classification of, 149-150 ; 

 origin of, 176. 



Ant-eater, its tongue, 120. 



Ant-lion, its habits, 353. 



Aponeurotic sheath, its function, 297. 



Arachnids, first established, 65 ; definition 

 of, 89 ; distinction from insects, 90 ; 

 classification of, 146-147 ; origin of, 

 176. 



Aristotle's Classification, 61 ; erroneous 

 direction of, 62. 



Artificial devices in natural science, 19 ; 

 enumeration of, 20. 



Attention, 380-384. 



Aura vitalis, 242. 



Bark, origin of, 234. 



Bats, flight of, 175. 



Bimana, definition of, 169. 



Birds, definition of, 75 ; effects of domes- 

 tication on, 110 ; use-inheritance in, 

 120; classification of, 163-166; origin 

 of, 177. 



Brain, derived from medulla oblongata, 



299. 



Cabanis, on the relations of moral and 

 physical, 185, 207 ; on life and feeling, 

 208 ; on sensibility and irritability, 

 228 ; on the functions of the brain, 302 ; 

 on sensation, 328 ; on melancholy, 338 ; 



on instinct, 351 ; on memory, 397 ; on 

 reasoning, 403. 



Caloric, see Subtle fluids. 



Carnivores, shape of, 123. 



Cellular theory, 230 et seq. 



Circulation, organ of, as indicating 

 natural affinities, 31 ; not found below 

 crustaceans, 89 ; a special faculty, 277 ; 

 its development, 277-278. 



Cirrhipedes, definition of, 86 ; classifica- 

 tion of, 150-151 ; origin of, 176. 



Class, definition of, 22. 



Classification, schematic, 21 ; uses of, 56 ; 

 direction of, 128 ; of animals, 131-133. 



Condillac, on the progress of reason, 185 ; 

 on language, 377. 



Crustaceans, first established, 65 ; defini- 

 tion of, 88 ; classification of, 148-149 ; 

 origin of, 176. 



Cultivation, effects of, on plants, 109. 



Death, peculiar to living bodies, 194 ; 



causes of, 264. 

 Degradation of organisation, 68. 

 Delirium, cause of, 395. 

 Digestion, physiology of, 267-268. 

 Disuse, effects of, 108 ; law of, 115 ; in 



whales' teeth, 115 ; in moles' eyes, 116 ; 



never affects organ of hearing, 116 ; 



in molluscs' heads, 117 ; in snakes' legs, 



117 ; in insects' wings, 118. 

 Dogs, origin of, 110. 

 Dreams, causes of, 341 ; their relation to 



memory, 394. 

 Drouming, effects of, 204. 



Echidna, see Monotremes. 



Echinoderms, 139. 



Education, errors of, 370 ; effects of, 383. 



Electricity, see Subtle fluids. 



Emotion, a function of the nervous system, 

 308; how produced, 332, 335; two 

 kinds of, 338 ; effects of, 338 ; causes 

 of, 340. 



Environment, affects organisation, 70 ; 



